At the end of October 2011, the world officially crosses the 7 billion mark in global population. In recent decades, population has increased by a billion people approximately every 13 years. The UN projects that the next billion will be added by 2024 and that world population will reach 9.3 billion by the middle of the century. Fertility rates, however, are declining in most countries and overall world population growth should slow considerably. But this trend masks considerable differences among countries. Many countries have already gone through a demographic transition from high fertility and high mortality to low fertility and smaller family size. Forty-two percent of the world’s population lives in countries where the fertility rate is below replacement level. Another forty percent lives in countries with slow-growing populations. The remaining eighteen percent are in high fertility countries, mostly in Africa and South Asia. It is these countries that will account for almost all population growth in years to come.

A family planning clinic in Afghanistan. Photo credit: Isobel Coleman

How quickly these high fertility countries transition to lower fertility will determine the world’s overall population. UN projections are highly sensitive to small changes in fertility. The difference between its medium projection and its high projection is just half a child more on average per woman, yet the result is a world population of nearly 16 billion by 2100, versus 10 billion under the medium variant. For countries with high fertility rates, women’s empowerment, female education, and access to voluntary family planning will determine the difference between these population projections.

Access to voluntary family planning is critical for enabling women to make decisions about the size of their families and the spacing of their pregnancies. In recent decades, use of modern family planning by women of reproductive age in developing countries has from less than 10 percent in 1965 to 53 percent in 2005. This represents an expansion of users from 30 million in 1960 to 430 million in 2008. Despite these gains, an estimated 215 million women globally still experience an unmet need for family planning. The vast majority lives in high fertility countries.

Ob-gyn clinic in rural Afghanistan. Photo credit: Isobel Coleman

Low rates of contraception use are linked not only to high fertility, but also to high rates of maternal and child mortality. Afghanistan, for example, has the highest rate of under-five mortality in the world and a contraceptive prevalence of only 10 percent. Many of the highest fertility countries today are also among the world’s most fragile states, with pressing economic, security and environmental challenges and the lowest levels of human development. They are the least able to provide opportunities for their burgeoning youth populations. High fertility rates can lead to a vicious cycle of poverty at the community, regional and national levels. The quality and availability of family planning services is instrumental in interrupting this cycle and creating stronger families and communities. Increasing access to voluntary family planning is one of the most cost-effective ways to improve health and reduce poverty while giving parents the tools to make critical decisions about the size of their families.